What is acute myeloid leukemia (AML)?
Acute myeloid leukemia (AML) or acute myeloblastenleukemie is a form of cancer that affects speficiek the myeloid line of the white blood cells. The myeloid lineage is responsible for the formation of granulocytes, monocytes, erythrocytes and megakaryocytes. Acute myeloid leukemia leads to an enormous proliferation of immature precursors of these cells in the bone marrow and usually also in the blood (leukocytosis). The rapid penetration of abnormal cells in the bone marrow interferes with the normal formation of blood cells (hematopoiesis). The
Symptoms of acute myeloid leukemia (AML) are caused by the replacement of normal bone marrow cells with leukemic cells. This causes the normal production of red blood cells (erythrocytes), platelets, and normal white blood cells (leukocytes) is compromised. Symptoms include fatigue, shortness of breath, bruising, bleeding and increased risk of infection.
Acute myeloid leukemia is the most common form of acute leukemia in adults, with an incidence that increases with age. Although acute myeloid leukemia is a relatively rare disease is responsible for about 1.2% of cancer deaths in the US Is expected by the aging of the population, the incidence of this condition will rise.
How many different risk factors for acute myeloid leukemia have already been identified, the cause of the disease to date remains largely unknown. Because it is an acute leukemia, the disease is rapidly progressive. Typically, the patient dies within a few weeks to months if left untreated. The five year survival rate is 15 to 70%, depending on the subtype of acute myeloid leukemia. Acute myeloid leukemia (AML) is initially treated with chemotherapy with the aim to bring the disease is in remission. Patients then received additional chemotherapy or hematopoietic stem cell transplantation. Recent studies on the genetics behind acute myeloid leukemia led to the availability of tests that can assess the efficacy of certain medications for an individual patient.
Epidemiology
Acute myeloid leukemia is a rare disease with about 3.7 / 100 000 new cases per year. The disease occurs mainly in the elderly, the median age is in the diagnosis of 63 years. Acute myeloid leukemia accounts for 80% of acute leukemias in adults. Men are slightly more affected than women (ratio 1.3 / 1). Childhood have only 15 to 20% of patients with acute leukcemie acute myeloid leukemia. In the rare event that acute myeloid leukemia is present in a newborn, but it is almost always acute myeloid leukemia.
The proportion of acute myeloid leukemia as a result of a previous chemotherapy treatment has been increasing; at this time are 10 to 20% of the cases of acute myeloid leukemia (AML) is the result of this treatment.
There is some noticeable geographical variation in the incidence of acute myeloid leukemia. In adults, the highest prevalence is seen in North America, Europe and Oceania. acute myeloid leukemia is rarer in Asia and Latin America. In contrast, childhood acute myeloid leukemia is less common in North America and India than in other parts of Asia. These differences are possibly due to genetic factors at the population level, environmental factors or a combination of both.
Acute myeloid leukemia is associated with genetic defects such as (trisomy 21 (Down's syndrome), Fanconi's anemia, and Bloom's syndrome. In addition, environmental conditions are referred to as the exposure to certain chemical substances, rays, tobacco, and chemotherapeutic agents. Haematological disorders in be associated with acute myeloid leukemia are paroxysmal nocturnal hemoglobinuria and malignancies myelodysplastic syndrome and other myeloproliferative disorders.
Clinical picture
Most of the symptoms of acute myeloid leukemia (AML) are caused by the replacement of normal blood cells (red blood cells, white blood cells and platelets) by leukemic cells. Complaints pertaining to this weakness and fatigability, infections, and the rise of bruising, bleeding gums, ecchymosis, epistaxis or menorrhagia. Often these symptoms in combination.
Fever
Fever, if present, can be associated in most cases with an infection. The policy is dependent on the presence or not presence of neutropenia, involving administration of a prompt breedsprectumantibioticum is indicated. If no clear neutropenia is present still exists the possibility of functional neutropenia. Here, there are normal amounts of neutrophils, but these are not functional. When a blood smear is microscopically assessed and the neutrophils herewith show certain features (such as a display or aspect hypogranulair dysplasia), this is suggestive of functional neutropenia. On the basis of such a functional neutropenia, may also be considered to administer antibiotics.
Leukemia can also give rise to fever in itself, even in the absence of an infection. This has previously been the case with acute promyelocytic leukemia.
Skin
The reduced number of blood cells can lead to certain events in the skin. Anemia, due to a reduced number of red blood cells, resulting in pale skin. A reduced number of platelets leads to petechiae and ecchymoses. acute myeloid leukemia affected in 13% of cases, the skin itself. This is called leukemia cutis. This can occur single or multiple red to purple-blue papules, plaques or nodules. Another appearance is a reddish-brown maculopapular eruption. The interval between the diagnosis and the appearance of the first manifestations of the disease on the skin varies widely. Sometimes, leukemia cutis is the first symptom of the disease.
Joints
About 4% -13% of patients with acute myeloid leukemia presenting with joint, and or bone pain. This inconvenience occurs in several joints, is generally symmetric and can migrate to other joints.
If there are painful, swollen joints are present in the context of an in the bone marrow and / or blood demonstrated leukemia, one speaks of leukemic arthritis. Other causes which could lead should then, however, be ruled out until it arthritis. Such leukemic arthritis is more common in children with leukemia than in older patients and more frequently in the context of an acute leukemia. Leukemic arthritis may already diagnosed with leukemia was asked to present, or later in the course of the disease arise.
Expansion of the bone marrow may also give rise to bone pain, this cause, however, always should be distinguished from leukemic arthritis, although both causes or may occur together.